Deep, diverse and definitely different:unique attributes of the world's largest ecosystem

• Published in: Biogeosciences
• Main Authors: Ramirez-Llodra, Eva, Brandt, Angelika, Danovaro, Roberto, De Mol, B, Escobar, Elva, German, Chris, Levin, Lisa, Martinez Arbizu, Pedro, Menot, Lenaick, Buhl-Mortensen, Pal, Narayanaswamy, Bhavani, Smith, C R, Tittensor, Derek, Tyler, Paul, Vanreusel, Ann, Vecchione, M
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2010
• Subjects: Ecology; GULF-OF-MEXICO; Geosciences; Multidisciplinary; SEA HYDROTHERMAL VENTS; SHRIMP ARISTEUS-ANTENNATUS; NORWEGIAN CONTINENTAL-SHELF; TROPICAL NORTHEAST ATLANTIC; CENTRAL ARCTIC-OCEAN; NEMATODE COMMUNITY STRUCTURE; CORAL LOPHELIA-PERTUSA; CENTRAL EQUATORIAL PACIFIC; MID-ATLANTIC RIDGE; Arctic; Arctic Ocean; Pacific; Mid-Atlantic Ridge; Lophelia pertusa; Northeast Atlantic
• Online Access: https://pure.uhi.ac.uk/en/publications/37af306a-01a4-4151-9ee1-214bb6846e52; https://doi.org/10.5194/bg-7-2851-2010

The deep sea, the largest biome on Earth, has a series of characteristics that make this environment both distinct from other marine and land ecosystems and unique for the entire planet. This review describes these patterns and processes, from geological settings to biological processes, biodiversity and biogeographical patterns. It concludes with a brief discussion of current threats from anthropogenic activities to deep-sea habitats and their fauna. Investigations of deep-sea habitats and their fauna began in the late 19th century. In the intervening years, technological developments and stimulating discoveries have promoted deep-sea research and changed our way of understanding life on the planet. Nevertheless, the deep sea is still mostly unknown and current discovery rates of both habitats and species remain high. The geological, physical and geochemical settings of the deep-sea floor and the water column form a series of different habitats with unique characteristics that support specific faunal communities. Since 1840, 28 new habitats/ecosystems have been discovered from the shelf break to the deep trenches and discoveries of new habitats are still happening in the early 21st century. However, for most of these habitats the global area covered is unknown or has been only very roughly estimated; an even smaller - indeed, minimal - proportion has actually been sampled and investigated. We currently perceive most of the deep-sea ecosystems as heterotrophic, depending ultimately on the flux on organic matter produced in the overlying surface ocean through photosynthesis. The resulting strong food limitation thus shapes deep-sea biota and communities, with exceptions only in reducing ecosystems such as inter alia hydrothermal vents or cold seeps. Here, chemoautolithotrophic bacteria play the role of primary producers fuelled by chemical energy sources rather than sunlight. Other ecosystems, such as seamounts, canyons or cold-water corals have an increased productivity through specific physical processes, such ...